Fusion furnace



A. F. GORTON ET AL FUSION FURNACE Filed April 27, 1925 Patented a. 19, 1926.

UNITED STATES PATENT OFFICE.

ARTHUR FEDDEMAN GORTON, OF BERWYN, AND WILLIAM HENRY GROVES, OF MEL- ROSE PARK, ILLINOIS, ASSIGNORS TO WESTERN ELEOTRIC COMPANY, INCORPO- RATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

I FUSION FURNACE.

Application filed April 27, 1925.

This invention relates to fusion furnaces and has for its main object the provision of an improved and simplified portable fusion furnace which may be operated efliciently and economically. I

According tothe main features of the 1n- .vention a vertical furnace of substantially cylindrical conformation is provided with a refractory lining havlng a constrlction at the bottom thereof. A plurality of removable pegs or pins of refractory material projecting through the side wall of the furnace may support a plaque spaced from the walls and upon which a material to be fused may be placed. A burner adapted to burn, w th a high temperature, a gas of high calorlfic value, such as acetylene, is vertically ad ust-- able within the constricted portion. The material being fused may be observed through an aperture in the side wall.

The invention will be more fully understood from the following detailed description taken with the accompanying drawings, in which Fig. 1 is a front elevation of a furnace and a support therefor embodying the main features of the invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a plan view, partially 1n section, of the furnace proper with portions thereof partly broken away, and

Fig. 4 is a fragmentary enlarged side ele vation partially in section showing a part of the mechanism for supporting the burner more in detail.

Referring now to the accompanylng drawings in which like numerals are employed to designate similar parts throughout the several views, a framework which may be of any suitable design supports a cylindrical furnace shell 11 by means of a plurality of legs 12, the furnace shell 11 and the legs 12 being of any suitable material, such as steel (Fig. 1). A refractory lining 13 1S separat ed from the outer shell 11 by a layer of nsulating material 14 such as asbestos (.Flg. 2). The lining 13 is suitably held in place by means of a supporting plate 13 wh ch may be made of any suitable material such as steel and may be a part of the shell 11 or secured thereto as desired. A plurality of apertures in the shell 11 and. lining 13 produce continuous apertures through the en-- Serial No. 26,006.

tire furnace wall through which a plurality of pegs 17 may be inserted and the innermost ends thereof cooperate to support a plaque 18. A cover, generally designated by the numeral 20, comprises a plurality of segments which may be fitted together to form a complete cover with a small aperture therein for the escape of hot gases in the manner shown particularly in Fig. 3. The pegs 17 the plaque 18 and the cover 20 are preferably made of the same material as the lining 13, but any material may be employed as long as it is sufliciently refractory.

The furnace may have a variety of uses,

but it is particularly adaptable for the testing of ceramic materials which are shown in the drawings in the shape of cones or pyramids 21, the bases of which have been embedded in a body of refractory cement 22. A slot-like aperture extending in a horizontal direction in the shell 11 coincides with a similar aperture in the lining 13 to form a continuous aperture 23 which affords the operator a view of the material being fused within the heating chamber.

The furnace is heated preferably by the forced combustion of a gas of high calorific value, such as acetylene or hydrogen, and in the accompanying drawing a single tip oxyacetylene torch or burner 24 having oxygen and acetylene intakes 25 and 26 and appropriate regulating valves 27 is shown mounted in an inclined channel shaped member 28 by means of a collar 30. The channel member is suitably supported on a member 31 which is slidable on a plurality of guides32. A chain 34 is suitably secured to the member 31 and to a counterweight 35, the chain 34 passing around a sprocket 37 which is keyed to a shaft 38 terminating in a handle 39 for adjusting the burner 24 vertically with respect to the lower portion of the furnace to alter the temperature thereof.

The lining 13 together with the other refractory portions of the furnace; namely, the plaque, the supporting pegs therefor, and the cover for the furnace may be 'made of any suitable refractory material, but very good results may be obtained by using fused magnesite in their manufacture. The magnesite may be substantially freed fromiron which is a natural constituent of the magnesite and the iron freemagnesite mixed with milk of magnesia as a bond and then fired; or commercial magnesite containing the normal percentage of iron may be employed and mixed with an organic binder, such as dextrine. In this case the dextrine acts as a bond until the firing of the material, and thereafter the fused iron will hold the structure together. This latter form may be used with good results because the lower extremity of the furnace permits a great deal of auxiliary oxygen to be admitted around the tip of the torch and this prevents the formation of a reducing atmo sphere within the furnace. It will be noted, however, that the lining 13 is slightly constricted at the lower portion thereof. With this arrangement the burner can be brought closer to the heating chamber without becoming heated to a point to cause backfiring.

Although the pegs 17 should fit sufiiciently snugly in the apertures in .the chamber walls to substantially close the same, they should nevertheless be loose enough to be easily removable. This arrangement permits easily and quickly changing the pegs, should the excess heat cause a cracking of these members. The pegs should preferably be made of the same material as the lining so that the two elements will contractand expand at the same rate and have no tendency to unite chemically at high temperatures.

In the fabrication of the refractory portions of the furnace it is necessary to avoid the use of materials which will unite chemically with the material being fused or otherwise tested, at a comparatively low temperature. For instance when employing the fun nace for testing purposes as will be described more in detail hereinafter, magnesite alone may cause a discoloration of the material being tested at a comparatively low temperature.

It will be noted that the flame traveling upwardly from the torch 24 encompasses the plaque 18 and that a uniformity of condition is maintained therearound and with respect to the material placed on the plaque. There is no appreciable cooling effect due to the location of the observation aperture 23 since some of the flame passes outwardly therethrough and prevents an influx of cold air at this point.- I

When employing the furnace for testing purposes the material to be tested is made into the form of a cone or pyramid and is preliminarily dried to make it self-sustaining. It is then embedded in a body 22 of suitable cement such as a mixture of kaolin and alumina together with a variety of standard cones or pyramids of the same size and shape of materials having known fusing temperatures. The cones are preferably placed in a regular formation and at the same distance from the center of the body of cement to insure uniformity of heating when placed in the furnace. The aggregation is ueoavaa then placed on the plaque 18 which is centrally located within the furnace. The furnacemay be preliminarily heated in any suitable manner such as with natural gas or may be heated by an acetylene burner of the type described. Whenemploying the acetylene burner 24 either when the furnace is cold or warm, the burner is lighted at a point somewhat below the furnace, and is then gradually raised by means of the ban dle 39 until the tip is slightly below the constricted portion of the furnace lining or at a somewhat lower point depending upon the condition desired in the furnace, it being possible to regulate the temperature of the furnace by the location of the burner; The burner may be raised slowly or quickly depending upon how fast it is desired or possible to increase the temperature of the furnace. When the furnace has been preheated, however, the burner may be raised more quickly than when the furnace is cold in starting. The burner is left in the attained position until the cones which are being tested start to fuse which condition is observed through the aperture 23 provided for that purpose after which the burner is lowered and the plaque bearing the cones is removed. This may be readily accomplished by raising the plaque by means of a suitable instrument such as a tri-pronged steel rod the plaque resting'upon the end of the rod and the three prongs thereof passing between the pegs 17. When the plaque has been raised clear of the furnace it may be removed from the rod in any suitable manner. The fusing (point of the cones which .are being teste is then determined by noting which of the standard cones are fused to the same degree as the tested cones, the fusing temperature of each of the standard cones being known.

One of the advantages of the furnace which is the subject matter of the present invention is its portability. It may be of small size and readily conveyed from place to place. Although specific reference has been madeto its use in the testing of ceramic materials, it may also be employed equally well for the fusion of precious metals or the like or for any purpose requiring extremely high temperatures. Although specific details are described, they are simply by way of illustration and to permit those skilled in the art to readily make use of the invention which is to be limited. however,

8 for heating the chamber, and means for comes in direct contact with the material to be fused.

2. In a furnace for fusing material, a

heating chamber having a constricted opening in the lower portion thereof, an element able'from the exterior thereof for supporting the plaque within but out of enga ement with the walls of the chamber, and a urner located below the plaque for directing heated gas against and around the pla ue.

4. In a furnace for fusing materlal, a heating chamber, means for holding material to be fused, means for supportin the material holding means within the c amber, means for heating the chamber, and means for varying the relative positions of the holding and heating means.

5. In a, furnace for fusing material, a heating chamber,means for holding mate- .rial to be fused, means supported by the chamber wall and removable from the exterior thereof for supporting the material holding means within the chamber, means varying the relative positions of the holding and heating means.

6. In a furnace for fusing material, a vertical heating chamber, means for holding material to be fused, means to support the material holding means, a burner located below the material holding means for heating the chamber, and means for moving the burner vertically relative to the holding {)neans to vary the temperature of the cham- 7. In a furnace for testing ceramic materials, a vertical heating chamber of cylin' drical formation and having an observation aperture in the side thereof, a plaque having a diameter substantially less than that of the interior of the chamber and adapted to hold cones of the material to be tested and of materials having known fusing temperatures, a lurality of members extending through t e wall of the chamber and individually removable from the exterior thereof for supporting the plaque with its peripheral edge substantially removed from the interior wall of the chamber, and a gas burner positioned below the plaque and adapted to direct a flame against the bottom of and around the plaque into direct and uniform contact with the cones thereon.

In witness whereof, we hereunto sub- 65 scribe our names this 15th day of April A. D., 1925.

ARTHUR FEDDEMAN GORTON.

WILLIAM HENRY GROVES. 

